GMC JIMMY FUEL PRESSURE PROBLEM

1999 GMC Jimmy • 120,000 miles

I just got done doing the head gaskets on my 99 Jimmy did the thermostat water pump plugs wires distributor cap rotor it starts then dies right away fuel pressure seams normal the iac is making a little noise but still works the engine tempature control sensor was replaced and had the transmission rebuilt. I don't know y it won't stay running, my gas gauge shows empty all the time and the oil pressure gauge shows all the way over, I'm pretty sure it might be the fuel oil pressure switch but I font know if that's it for sure and I don't know were it's located. PLEASE HELP ME GET MY JIMMY RUNNING AGAIN.